2. The value of the z-score in a hypothesis test is influenced by a variety of factors. Assuming that all other variables are held constant, explain how the value of z is influenced by each of the following:

1. Increased the difference between the sample mean and the original population mean.
2. Increased the population standard deviation.
3. Increased the number of scores in the sample.

4. If the alpha level is changed from ð=0.5 to ð=.01,

1. What happens to the boundaries for the critical region?
2. What happen to the probability of a Type I error?

6. A researcher is investigating the effectiveness of a new study-skill training program for elementary school children. A sample of n=25 third grade is selected to participate in the program and each child is given a standardized achievement test at the end of the year. For the regular population of third grade children, scores on the test form a normal distribution with a mean of µ=150 and a standard deviation of ð=25. The mean for the sample is M=158.

1. Identify the independent and the dependent variables for this study.
2. Assuming a two tailed test, state the null hypothesis in a sentence that includes the independent variable and the dependent variable.
3. Using symbols state the hypothesis (H⁰and H₁) for the two tailed test.
4. Sketch the appropriate distribution, and locate the critical region for ð=05.
5. Calculate the test statistic (z-score) for the sample.
6. What decision should be made about the null hypothesis, and what decision should be made about the effect of the program?

10. State College is evaluating a new English composition course for freshman. A random sample of n=25 freshman is obtained and the students are placed in the course during their first semester. One year later, a writing sample is obtained for each student and the writing samples are graded using a standardized evaluation technique. The average score for the samples is M=76. For the general population of college students, writing scores form a normal distribution with a mean of µ=70.

1. If the writing scores for the population have a standard deviation of ð=20, does the sample provide enough evidence to conclude that the new composition course has a significant effect?
2. If the population standard deviation is ð=10, is the sample sufficient to demonstrate a significant effect? Again, assume a two-tailed test with ð=.05.
3. Briefly explain why you reached different conclusion for part (a) and part (b).

12. To test the effectiveness of a treatment, a sample of n=25 people is selected from a normal population with a mean of µ=60. After the treatment is administered to the individuals in the sample, the sample mean is formed to be M=55.

1. If the population standard deviation is ð=10, can you conclude that the treatment has a significant effect? Use a two-tailed test with a ð=.05
2. If the population standard deviation is ð=20, can you conclude that the treatment has a significant effect? Use a two-tailed test with a ð=.05.
3. Compute Cohen’s d to measure effect size for both tests (ð=20 and ð=10).

22. Explain how the power of a hypothesis test is influenced by each of the following. Assume that all other factors are held constant.

1. Increased that alpha level from .01 to .05
2. Changing from a one-tailed test to a two-tailed test.

24. A researcher is evaluating the influence of a treatment using a sample selected from a normally distributed populated with a mean of µ=80 and a standard deviation of ð=20. The researcher expects a 12-point treatment effect and plans to use a two-tailed hypothesis test with ð=.05.

1. Compute the power of the test if the researcher uses a sample of n=16s.
2. Compute the power of the test if the researchers uses a sample of n=25 individuals.

There are two parts to this assignment:

• First, using SPSS, you must use the Analyze, Descriptive Statistics, Frequency commands to generate frequency data for all of the categorical variables and the Analyze, Descriptive Statistics; Descriptive commands to generate means and standard deviations for your continuous data. Once you calculate all of this information, you must copy and paste all the relevant tables into your application file (see below).
• Second, you must generate an formatted write-up that includes the following: (a) A text paragraph describing the information about these variables (e.g., percentage of men and women, average IQ, etc.) and (b) an APA formatted Table
• Using the Final Project Template, complete a working draft of your Final Project. Note that at this time, you will not complete all sections of the template. Your draft should include the following sections and use correct APA format:
  • Title Page: Fill in the information indicated in the template.
  • Abstract: A working copy of your abstract. This will be need to be revised before submitting your final project in Week 11 to include your results.
  • Introduction: 1-2 pages in length
  • Method: Provided in the template
  • Results: Descriptive Statistics, including APA formatted Table(s) (from Week 3 assignment)

Price: $18.48

Solution: The downloadable solution consists of 6 pages, 1248 words and 1 charts.
Deliverable: Word Document